(1) Field of the Invention
The invention relates to the apparatus of the kind disclosed in U.S. Pat. No. 4,052,165, granted Oct. 4, 1977, for separating by centrifugal force the components of samples and then measuring them. The samples are placed in rod-like vessels and are kept in place by means of a fixing part in radial recesses of a plate-like rotor of the apparatus. The fixing part is able to be moved in the axial direction of the rotor and is acted upon by a return spring having a tendency to keep it in a first stop position for putting in the vessels before they are fixed in position. The fixing part has in it at least one locking part for use with a locking nosepiece on the rotor and which keeps the fixing part in a second stop position, once the vessels have been fixed in position, against the effect of the return spring.
(2) Overview of the Invention
One purpose of the present invention is that of making such a further development of the apparatus of the main patent application that in one form of the apparatus the plate-shaped rotor is able to have its place taken by another one. For effecting this purpose the rotor plate is able to be joined with the driving shaft by a driving coupling able to be undone, and the nosepiece for use with the locking part is placed on the part, fixedly joined to the driving shaft, of the driving coupling. One good effect of being able to make use of one or more different rotor plates is that of ready cleaning of dirt from the rotor. Such dirt is produced by putting in place and taking out full capillary tubes or vessels a number of times. The cleaning made possible by the invention takes place in a very simple manner after the rotor has been taken off, without making the other parts of the apparatus dirty. Furthermore the use of an other rotor plate as a single part in place of the rotor plate which has been damaged by wear after being used for a long time, is readily possible. This is specially important with respect to low-price servicing and putting in new parts.
In a more particular form of the invention the driving coupling is so designed that the taking off of the rotor plate together with the fixing part and the locking lever is possible by pulling out in the direction of the driving shaft.
A coupling and locking system, which is able to be made with the least number of parts, is made possible by an other measure of the invention because the part, fixedly joined to the driving shaft, is in the form of a coupling part with axially running coupling teeth, which go into the necessary coupling grooves in the rotor plate, and the edge of the coupling part is designed on the one hand as a support for the rotor plate and on the other hand as locking nosepiece for use with the locking lever. This is a form of the invention of good effect in which parts of the coupling shaft is outside the coupling piece and at this position makes for a guide pin, on which the hub of the rotor plate is guided. The hub is made longer in the middle.